Red flags unfurled and waved wildly in my mind when I saw
this article from Food Safety Magazine: “High Arsenic Levels Found in U.S.
Chicken.” The original article can be
viewed here: http://www.foodsafetymagazine.com/news/high-arsenic-levels-found-in-us-chicken/. Now, arsenic can be a deadly thing; after
all, it’s often the poison of choice in melodramas. Just a small amount can be lethal: an oral
dose of 60 mg is fatal to the average human (Minnesota Department of Health,
2012). However, would companies really sell chicken meat that contains a
known poisonous substance? And just how
reliable is the research that this article quotes? Let’s take a closer look at the facts:
The Food Safety Magazine article alludes to “Arsenic species
in poultry feather meal” published in a 2012 volume of Science of the Total Environment.
Rather than testing arsenic levels in chicken meat that would be
directly eaten, the researchers looked at arsenic levels in feathers, which are
not directly eaten by consumers. The
researchers reasoned that since feather meal is often used a protein source for
fertilizers and animal feeds, the use of arsenic-tainted feather meal for these
purposes could have harmful effects on humans.
This is a well-intentioned but perhaps unnecessary concern. After all, the researchers found the
concentration of inorganic arsenic in their samples was approximately 2 parts
per billion (National Chicken Council, 2013).
The maximum contaminant level for arsenic in drinking water is 10 parts
per billion (Environmental Protection Agency, 2012). The average level of arsenic in soil is 3-4
parts per million (Agency for Toxic Substances and Disease Registry, 2011). Therefore, the chicken feathers contained
less arsenic than may be found in both water and soil.
* * *
Another issue with the Science
of the Total Environment article is the reference to the product roxarsone, allegedly added to the diets of broilers (chickens raised for meat production). However, the researchers admitted that no
connection between roxarsone and the presence of inorganic arsenic in feathers
could be found:
“In this study we had no information on the precise contribution
of roxarsone to inorganic arsenic exposure in feather meal.” (Nachman, Raber,
Frcesconi, Navas-Acien & Love, 2012).
Still, the researchers expressed their continued concern
about the use of this product:
“However, given the
common use of roxarsone in poultry production, the increase in inorganic arsenic
exposure in livers of chickens fed roxarsone, and the likely accumulation of
inorganic arsenic in feathers, inorganic arsenic measured in feather meal in
this study may have originated from the practice of administering roxarsone to
broiler chickens in the context of industrial poultry production.” (Nachman, et
al., 2012).
However, this concern is virtually unfounded today: since
June 2011, roxarsone has no longer been used to supplement the diets of
broilers (National Chicken Council, 2013).
* * *
The last detail to raise doubt in this study is the
relatively small sample size from which arsenic levels were determined. Samples of feathers came from twelve
locations: one each from Tennessee, Pennsylvania, California, and Idaho; two
from Arkansas, four from Oregon, and two from China (Nachman, et al., 2012). However, the specific locations and suppliers
from whence the feathers came were not mentioned. Basing analyses on such a small sample and
not disclosing the origins of the sample materials is ill-practice
in the world of peer-reviewed journals (Hofacre, 2012). These samples might have all come from farms
raising “free-range” broilers experiencing greater contact with soil and unregulated
water sources, or from farms raising conventional broilers living in a controlled,
indoor environment. Such different
rearing methods could arguably result in different levels of exposure to
arsenic.
In conclusion, since arsenic is present in the air, water,
and soil, it’s not surprising a small amount would end up on chicken feathers. But remember, the arsenic levels found on the
feathers were extremely low, and if contaminated feathers might pose a problem
when added to fertilizers or animal feeds, they would not be added. Given the thorough processing feathers endure
before they are included in fertilizers or feeds, there is adequate time to
check for feather quality and the presence of any contaminants (Moritz &
Latshoaw, 2001). But again, the arsenic is appearing on feathers, not meat. In fact, the U.S. Department of Agriculture
monitors chicken meat for arsenic levels, and in the past 20 years has found zero samples that violate the level set
by the U.S. Food and Drug Administration (National Chicken Council, 2012). With strict guidelines in place for levels of components in meat, milk, and all manner of animal
products, the U.S. food supply is kept as safe as possible.
Agency for Toxic Substances and Disease Registry. (March 3, 2011). Toxic substances portal – arsenic. Retrieved from http://www.atsdr.cdc.gov/phs/phs.asp?id=18&tid=3#bookmark03
Environmental Protection Agency. (May 21, 2012). Basic Information about arsenic in drinking water. Retrieved from http://water.epa.gov/drink/contaminants/basicinformation/arsenic.cfm
Hofacre, C.L., (2012, April 24). Bloomberg chicken study is
flawed. The Baltimore Sun. Retrieved
from http://articles.baltimoresun.com/2012-04-24/news/bs-ed-chicken-study-letter-20120424_1_peer-review-chicken-samples
Minnesota Department of Health. (November 21, 2012). Arsenic. Retrieved from http://www.health.state.mn.us/divs/eh/hazardous/topics/arsenic.html#health
Moritz, J.S. & Latshaw, J.D. (2001).
Indicators of nutritional value of hydrolyzed feather meal. Poultry
Science, 80, 79-86.
Nachman, K.E., Raber, G., Francesconi, K.A., Navas-Acien,
A., & Love, D.C. (2012). Arsenic species in poultry feather meal. Science
of the Total Environment, 417-418, 183-188.
National Chicken Council.
(September 18, 2012). Arsenic
& chicken? No need to worry.
Retrieved from http://www.nationalchickencouncil.org/arsenic-chicken-no-need-to-worry/
National Chicken Council.
(May 11, 2013). NCC responds to
misleading Johns Hopkins study; says arsenicals no longer fed to broilers. Retrieved from http://www.nationalchickencouncil.org/ncc-responds-to-misleading-johns-hopkins-study-says-arsenicals-no-longer-fed-to-broilers/
Minnesota Department of Health. (November 21, 2012). Arsenic. Retrieved from http://www.health.state.mn.us/divs/eh/hazardous/topics/arsenic.html#health
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